In the area of online advertising, an advertiser, such as a company that is selling goods or services or a non-profit entity advancing a particular cause, pays a website owner, known as a “publisher,” to include the advertiser's advertisements into one or more of the publisher's webpages. An advertiser may have its advertisements displayed through multiple publishers or third party advertising networks/brokers, and a publisher may display advertisements from multiple advertisers or third party advertising networks/brokers on any one of its webpages.
FIG. 1 depicts an example of a publisher webpage 120 that includes a plurality of advertisements 131-133. Advertisements 131-133 may comprise image files, Flash™ files, textual elements, or any other kinds of objects or elements that may be used to market products or services. Typically, rather than hosting advertisements 131-133 directly on its server, the publisher will include links or elements (known as “ad-codes”) into the hypertext markup language (HTML) of webpage 120. The ad-codes will instruct users' browsers to retrieve advertisements from ad-servers operated by advertisers or from ad-servers operated by third-party intermediaries, such as advertising networks or brokers. FIG. 1 depicts an exemplary webpage 120 as it might be rendered by a web browser 110 on a client device after having retrieved both the HTML of the webpage from the publisher and advertisements 131-133 from their respective advertisers or third party advertising networks.
In an impression- or view-based advertising compensation model, a publisher may earn a commission from an advertiser each time that a webpage containing an advertisement is viewed by a user. Typically, an advertiser or ad-server will track the number of distinct views by simply counting the total number of hypertext transfer protocol (HTTP) requests made by users to download the advertisement from a server operated by the advertiser or third-party ad network that hosts the advertisement file(s). However, one significant drawback to this approach is that even if an advertisement is downloaded by a browser, it may never actually be displayed in a visible area of its parent webpage and, thus, could not actually be viewable by a user.
For example, FIG. 2 depicts publisher webpage 120 in its entirety—that is, representing all of the content encoded in its corresponding HTML file. FIG. 2 also depicts the viewport 112 of browser 110 in the form of a dashed-line box. Viewport 112 may represent the portion of webpage 120 that is being displayed in or otherwise in focus within browser 110 at any given time. By comparing FIGS. 1 and 2, it can be seen that viewport 112 encompasses only a portion of webpage 120, with the rest of the page running outside the visible area of the browser, a phenomenon sometimes referred to as “page-clipping.” For example, although advertisements 134 and 135 are also included within webpage 120, these advertisements will not be displayed in viewport 112 unless a user instructs browser 110 to scroll downward.
Moreover, even if an advertisement is contained within the viewport of a browser, there may be other reasons why it may nevertheless not be visible on a client device screen. For example, as depicted in FIG. 3, in some operating systems, the window of browser 110 may be positioned within a graphical user interface (GUI) desktop 300 such that a portion of the window runs off of the visible area of the device screen, a phenomenon sometimes referred to as “screen-clipping.” In the example of FIG. 3, even if advertisements 131-133 were within the viewport of browser 110, such advertisements might never be displayed to a user if they were positioned only within a screen-clipped area of the viewport.
Similarly, as depicted in FIG. 4, objects within a webpage might not be visible to a user, even if they are included in the viewport of the browser, if they are positioned within an area of the viewport that is obscured by another window or object. For example, as depicted in FIG. 4, although advertisements 131-133 are within the viewport of browser 110, only advertisement 133 is visible, advertisements 131 and 132 being obscured by another window 400.
An advertisement may not be visible, or fully visible, on a device screen for other reasons, despite having been downloaded by a browser. For example, a webpage may be downloaded and rendered in a separate browser window or tab that the user never brings to the foreground, or an advertisement may be contained within an area of a publisher webpage that has smaller dimensions than the dimension of the advertisement, in which case the advertisement may be only partially displayed.
In any of these and other cases in which an advertisement is downloaded but not displayed, or not fully displayed, on a client device screen, an advertiser or third-party ad network may nevertheless credit the publisher with a view, since, absent manual inspection of the publisher webpage, the advertiser or third-party ad network will know only that the advertisement was downloaded by the user. Asia result, advertisers may pay commissions for a significant number of downloaded advertisements that were never actually visible (or could never have been visible) to users. This could result in advertisers being susceptible to fraudulent activity designed to illegitimately increase impression counts without actually displaying the requested advertisements to end-users.
Accordingly, online advertising may be improved by techniques for determining accurate view-counts for electronic advertisements that do not rely merely on download statistics, but are also able to determine whether electronic advertisements have been displayed in a viewable area of client device screens.